The stock setup has a groove mount plate and an assembly that is just too heavy. As much as it is better than a lot of other groove mount implementations, I see that it can be made better.
This last image is a sneak peak at the difference the upgraded carriage makes and how it brings things to the next level. It shows over 900g can become low 6xx grams and that is with a bigger, stronger mgn12 rail instead of the stock mgn9. A lot of the weight is no longer tossed around in the cable chain, and the loads are now inline with each axis, so there is less resonance and less inertia in awkward planes. What started as a dual extrusion and 2.4 style cable chain has turned into much more and really (in my opinion) brought this printer into a whole different category. It is probably going to perform at the top of that “$10k range printer” level.
This are the dragon mount and the 5015 fan shroud download links.
I do have stock fan shrouds too, but I think I have to adjust the height to work with the dragon and other short hotends, as I have modified these for someone with a stock setup when I first got the printer.